1. Field of the Invention
The present invention pertains to the art of washing machines and, more particularly, to a washing machine incorporating a system for detecting and displaying when high suds level conditions develop while laundering articles of clothing in the washing machine.
2. Discussion of the Prior Art
The development of suds during operation of an automatic washing machine is a problem that has been recognized in the art. Actually, high levels of suds can form throughout various cycles of a washing operation. In more conventional vertical axis or top-loading washing machines, high levels of suds can be developed during a wash cycle when a water/detergent solution which has a rather high detergent content is placed in turbulence by the operation of an agitator. For front-loading washing machines, the potential of developing high levels of suds can be even greater during wash cycles given the tumbling action of the clothes through the water/detergent solution. In each of these types of known washing machines, high levels of suds can also develop during spin cycles due to the creation of turbulent air when a washing machine basket is rotated at high RPMs. More specifically, during spin cycles the water/detergent solution is directed into a drainage zone by the centrifugal force of the rotating washing machine basket and combines with the turbulent air in the drainage zone to generate suds that can flow back into the basket.
At the end of a wash cycle in either a top or front-loading washing machine, the water/detergent solution is subjected to a drainage operation, followed by a spin period for the washing machine basket. It is desired to remove as much of the water/detergent from the clothes as possible during these steps. Thereafter, the clothes are subjected to various rinse cycles, during which the clothes are agitated or tumbled within fresh water supplied within the basket. Each rinse cycle may also terminate in sequential draining and spinning operations. The development of high levels of suds can be problematic during both the wash and rinse cycles for various reasons. For instance, whenever the washing machine enters a spin mode, the presence of high levels of suds can produce a heavy and possibly excessive load on the motor used to drive the washing machine basket. In addition, the development of high levels of suds may result in a residual water/detergent solution remaining in the laundered clothes, even if several rinse cycles are incorporated in the overall washing operation.
The prior art has addressed this known problem in various fashions. In general, each of the proposed solutions focuses on the reduction of suds during a particular cycle or mode of operation of the washing machine. For example, U.S. Pat. No. 4,410,329 is directed to correcting an over-suds condition that develops during a wash cycle. More specifically, when the over-suds condition is sensed, the wash cycle operation is suspended to enable the clothing and suds in the basket to be sprayed with cold water for a preset period of time and then the clothes are allowed to cool while the bubbles collapse before the washing operation is resumed. Another solution is proposed in U.S. Pat. No. 5,596,889 which is solely directed toward the elimination of high levels of suds produced during spin cycles. In accordance with this patented arrangement, each spinning operation is carried out in multiple stages, with the washing machine basket being rotated at varying speeds during the individual stages. Finally, U.S. Pat. No. 5,890,247 discloses a suds detection and control system which functions to alter the mechanical actions imparted upon articles of clothing during wash and rinse cycles and/or add a supplemental rinse cycle to an overall washing operation in response to an indication of a high suds level condition in the machine.
To date, known prior art suds control systems only address the problem by directly, automatically counteracting a suds condition following detection thereof. Therefore, the user of the washing machine is not actually provided with any indication that an over-suds condition even developed. Since the over-suds condition can be directly attributed to the manner in which the washing machine is operated by the user, the prior art really fails to address the source of the problem. Based on the above, there exists a need in the art for a system designed to notify the user when over-suds conditions are detected in at least a certain number of cycles, as well as to educate the user of the machine on how to avoid developing similar conditions in future cycles.
The present invention is directed to a control system for a clothes washing machine which is automatically responsive to indications of high suds level conditions during washing operations to, not only effectively counteract the high level of suds, but effectively educating the user on avoiding the reoccurrence of the conditions. Most preferably, a display, such as an LCD touch screen which is also preferably used to input desired cycle parameters, is integrated into the washing machine for conveying information to the user on how to avoid the development of future over-suds conditions.
In accordance with the invention, a high suds level condition is preferably indicated by detecting an operating parameter of the washing machine, such as the motor torque, which may be affected when high levels of suds exist. Signals from the detection unit are preferably correlated into torque values for the drive system and current torque values are compared with stored values to determine when a load is placed upon the drive system which is indicative of the presence of high levels of suds. Regardless of the particular type of suds detection system employed, it is preferable to instruct the user only after a predetermined number of high level suds cycles are detected. More specifically, the most preferred embodiment of the invention provides for informing the user when four out of the last seven cycles have been designated as high suds cycles. In addition, further instructions can be presented through the display to guide the user on eliminating the problem. If the user actually notices that the washing tub is full of suds upon termination of a laundering operation, instructions can be directly accessed through the display by the user. The invention is applicable to various types of washing machines, including vertical axis machines and, particularly, front-loading machines.